NEW: Adding method to News Holder to be used for pagination with multipl...

Was unable to use a SubSections loop with pagination on a holder page that contained child holder pages which in turn contained child article pages, because the pagination details were being grouped to the child holder pages.

So if I had a Holder page with 2 child holder pages which both contained 9 articles pagination would not work.
Created a new method TotalChildArticles which returns a grouped Datalist so for the example above the Datalist would contain 18 items.